Squirrel cage blower puller device



July 23, 1968 R. K. BREWER 3,393,442

SQUIRREL CAGE BLOWER FULLER DEVICE Filed March 13, 1967 FIG. 1

INVENTOR ROBERT K. BREWER k\ F a 4 BY WW- ATTORNEY United States Patent3,393,442 SQUIRREL CAGE BLOWER PULLER DEVICE Robert Keener Brewer, 1800De Charles St., Tyler, Tex. 75701 Filed Mar. 13, 1967, Ser. No. 622,5693 Claims. (Cl. 29-259) ABSTRACT OF THE DISCLOSURE A substantiallyrectangular body having a circular socket in an edge thereof foraccommodating the hub of the blower and a smaller bore coaxial with thesocket for receiving the end of the shaft. There is a locking slotextending into the socket for receiving the partially unthreadedset-screw of the hub and a puller screw threaded into the body coaxialwith the socket and bore to urge against the end of the shaft when thebody is locked in position on the blower hub.

The present invention relates to a device for removing from a shaft asquirrel cage blower, pulley and the like having a hub secured to theshaft by a set-screw, more particularly, to such a device having arectangular body which is relatively thin so as to be able to fit in thesmall clearance between the edge of the blower and the air-conditionercasing to fit the device over the blower hub and shaft end.

When a window air-conditioner unit has been in operation for severalyears, it may become necessary to replace the fan motor or todisassemble the unit for repairs. After such a unit has been in use fortwo to three years the motor shaft upon which the squirrel cage bloweris mounted becomes rusty. As a result, the hub of the blower becomesextremely tightly secured to the shaft and considerable force isnecessary to remove the blower from the shaft. In some instances itbecomes necessary to cut off the motor shaft to remove the motor itselfand then press the shaft out of the squirrel cage blower. Thisprocedure, however, takes a considerable amount of time. In addition,the removal of the blower from the shaft is further complicated by thesmall clearance provided between the edge of the squirrel cage blowerand the unit casing. In some instances this space is only about 1 /2inches and it is extremely difficult even for a person to insert hishand in this space when he is considering removing the blower from theshaft.

It is therefore the principal object of the present invention to providea novel and improved device for removing the squirrel cage blower fromthe motor shaft in a window air-conditioner unit.

It is another object of the present invention to provide a readilyoperable and effective device which can be easily used in limited andconfined spaces for removing from a shaft squirrel cage blowers, pulleysand the like having a hub secured to the shaft by a set-screw.

The objects of the present invention are achieved and the disadvantagesof the prior art are eliminated by the device according to the presentinvention which in one aspect may comprise a substantially rectangularblock-like body having a pair of opposed faces with the thicknessbetween the opposed faces being somewhat less that the diamter of thehub upon which the device is to be used. A bore or socket is provided onone edge of the body and has a diameter slightly greater than thediameter of the hub so as to receive the hub therein. The bore or socketopens to both of the opposed faces. A locking groove is formed in one ofthe opposed faces of body and extends into the bore. A second lockinggroove may be provided on the other opposed face. A set-screw isthreaded into the body to engage the periph- 3,393,442 Patented July 23,1968 eral surface of a hub received within the bore so as to grip thehub within the device. A second bore is provided in the body openinginto the first bore and coaxial with the first bore for receiving theend of the shaft which may protrude outwardly of the hub. A puller screwis threaded into the body coaxial with the first and second bores andextending into the second bore when threaded into the body a portion ofits length so as to engage the end of a shaft received therein. Thepuller screw may have a square head so that a wrench or the like can beused to turn the puller screw when the device is positioned over thehub.

To remove the blower from its shaft, the hub setscrew is unthreaded to aprotruding position and the device is placed over the shaft end toreceive the hub and shaft in the first and second bores respectively.The device is then slightly rotated so that the protruding hub set-screwis positioned Within the locking groove. The puller screw is thenthreaded into the body to engage the end of the shaft and to push theshaft inwardly away from the hub while the hub, by means of theset-screw, is retained in the device.

Other objects and advantages of the present invention will be apparentupon reference to the accompanying description when taken in conjunctionwith the following drawings wherein;

FIGURE 1 is a side elevational view of a portion of the interior of awindow air-conditioner unit with the squirrel cage blower beingpartially cut away to illustrate the device of the subject invention inposition on the hub;

FIGURE 2 is an overall perspective view of the device of the presentinvention together with a portion of the shaft and the hub which isreceived within the device;

FIGURE 3 is an end view of the socket end of the device of FIGURE 2; and

FIGURE 4 is a sectional view taken along the line 4-4 of FIGURE 3.

Proceeding next to the drawnigs wherein like reference symbols indicatethe same parts throughout the various views a specific embodiment of thepresent invention will be described in detail.

While the device of the present invention is capable of a wide range ofuses it is particularly adapted for removing the squirrel cage blowerfrom a window airconditioner unit. In FIGURE 1 a portion of such a unitis illustrated and there is shown a squirrel cage blower 1 having a hub2 and mounted on a motor shaft 3 journaled in a wall 4. Closely spacedfrom the open end of blower 1 is a housing 5 for cooling coils 6. Thespace between the blower and the housing is generally of the order ofabout 1 /2 inches. The blower hub 2 is secured to the shaft by means ofset-screw 7. Positioned on the hub 2 is the device of the presentinvention indicated generally at 8 and shown in greater detail in FIGURE2.

The device 8 comprises a block-like body 9 which may be rectangular incross-section and has opposed fiat faces 10 and 11. The thickness of thebody which is the distance between opposed faces 10 and 11 is preferablyless than the diameter of hub 2.

There is a bore or socket 12 formed in edge 13 of the body with adiameter slightly greater than that of the hub 2 so as to closelyreceive the hub therein. As indicated at 14 the socket 12 will open toboth of the opposed faces 10 and 11.

A locking groove 15 is formed in one or both of the opposed faces 10 and11 and opens to the socket 12.

There is a second bore within the body 9 and indicated at 16 in FIGURE4. The bore 16 is for the purpose of accommodating the end of shaft 3protruding outwardly beyond hub 2. The bore 16 is coaxial with the boreor socket 12. There is a coaxial bore 17 threaded into the body 9 forreceiving a puller screw 18 having preferably a square head 19. Thepuller screw is of sufiicient length so that when at least partiallythreaded into its bore 17 it engages the end of motor shaft 3.

There is a lateral bore 20 in the body 9 for accommodating a set-screw21 which engages the outer periphery of the hub when the hub ispositioned in socket 12 to grip the hub within the device.

As many be seen in FIGURE 3 a second locking groove 22 may be providedon face 10.

In using the puller device of the present invention, the blowerset-screw 7 is first loosened by an Allen wrench and then backed off sothat set-screw protrudes about A; of an inch above the surface of hub 2.In some instances it may be desirable to remove the hub set-screwcompletely and insert an Allen cap screw with an unthreaded shankportion and then threading the threaded portion of the cap screw intothe hub. This would result in a portion of the cap screw protrudingoutwardly of the hub periphery.

The puller device 8 which is less than 1 inch thick can then be readilyinserted between the blower and the casing and positioned over the hub 2and shaft 3 as shown in FIGURE 1. The device is then rotated slightly sothat the protruding set-screw 7 is received in one of the lockinggrooves or 22.

The shaft 3 is then suitably gripped so as to prevent its rotation and awrench such as indicated at 23 in FIGURE 1 is placed over the squarehead 19 of the puller screw 18. By means of the wrench, the puller screwis threaded into the body to engage the end of shaft 3. Continuedthreading of puller screw will push the shaft inwardly with respect tothe hub 2 while the hub remains stationary and is prevented from axialmovement by means of the device 8. Because of the tremendous forceexerted by the puller screw against the shaft the hub is unloosened fromthe shaft. Once the blower has been loosened from the shaft, the motorand shaft can be backed up and the blower then rolled out of the unit oras shown in FIGURE 1 can be lifted laterally upwardly from the unit. Itis thus apparent that both the motor shaft and the squirrel cage blowerare undamaged and can be reused.

It is understood that the socket or bore for accommodating the hub canbe made of different diameters in order to accommodate different sizedhubs. Generally speaking, there are four conventional sizes of squirrelcage blowers used in such air-conditioner units and accordingly aseparate wrench must be provided for each of these blowers. However, thebody of the device of the present invention could be readily modified toaccommodate inserts with each insert having a socket or bore for fittinga particular size blower hub.

It is estimated that in about 75-85 percent of the time the squirrelcage blower set-screw can be used as the lock for the puller device ofthe present invention. In those cases where the set-screw cannot beused, a cap screw can be inserted in its place as described above.

Thus it can be seen that the present invention discloses a wrench typedevice which can be effectively employed to remove blowers, pulleys andother similar structures having a hub mounted on a shaft. The presentdevice is particularly useful in those installations where accessibilityto the hub mounted on the shaft is particularly difiicult or limited.The present device is extremely simple in structure and function andeffectively utilizes the set-screw of the hub for locking the hub withinthe device while an axial force is exerted against the shaft upon whichthe hub is mounted by means of the puller screw in the device. The useof the subject device in removing squirrel cage blowers not only saves aconsiderable amount of time, but also enables the blower and motor shaftto be used again since neither is damaged during the removal process.

It will be understood that this invention is susceptible to modificationin order to adapt it to different usages and conditions, andaccordingly, it is desired to comprehend such modifications within thisinvention as may fall within the scope of the appended claims.

What is claimed is:

1. A device for removing from a shaft a squirrel cage blower, pulley andthe like having a hub secured to the shaft by a set-screw, andcomprising a block-like body having a pair of opposed faces, there beinga bore in an edge of said body having a diameter slightly greater thanthe diameter of said hub so as to recevie the hub therein, means on saidbody comprising a locking groove extending radially from said bore forlockingly engaging said hub set-screw against axial movement of said hubwhen said hub is received Within said body first bore, there being asecond bore in said body opening into said first bore, and coaxialtherewith for receiving the shaft end, means on said body for grippingthe hub when said hub is with in said first bore, a puller screwthreaded into said body coaxial with said first and second bores andextending into said body coaxial wit-h said first and second bores andextending into said second bore when partially threaded into said bodyso as to engage the end of the shaft received therein, the device beingplaced over the shaft end to receive the hub and shaft in the first andsecond bores respectively after the hub set-screw is unthreaded to aprotruding position and the device being rotated to receive the hubset-screw within said set-screw locking means whereupon the puller screwis threaded into the body block to loosen the shaft from the hub.

2. A device as claimed in claim 1 wherein the thickness between saidopposed body faces is less than the diameter of the hub, said first boreopening to both of said opposed faces and said locking groove being inone of said opposed faces and extending into said first bore.

3. A device as claimed 1 with said hub locking means comprising aset-screw threaded within said body and engageable with the peripheralsurface of said hub when the hub is received within said first bore.

References Cited UNITED STATES PATENTS 1,318,l37 10/1919 Dunlap 292631,355,028 10/1920 Blessing et al 29263 1,857,211 5/1932 Odlum et al29-257 1,956,924 5/1934 Kulp et al. 29259 MYRON C. KRUSE, PrimaryExaminer.

